101
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Yu L, Shen HY, Coelho JE, Araújo IM, Huang QY, Day YJ, Rebola N, Canas PM, Rapp EK, Ferrara J, Taylor D, Müller CE, Linden J, Cunha RA, Chen JF. Adenosine A2A receptor antagonists exert motor and neuroprotective effects by distinct cellular mechanisms. Ann Neurol 2008; 63:338-46. [PMID: 18300283 DOI: 10.1002/ana.21313] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To investigate whether the motor and neuroprotective effects of adenosine A(2A) receptor (A(2A)R) antagonists are mediated by distinct cell types in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease. METHODS We used the forebrain A(2A)R knock-out mice coupled with flow cytometric analyses and intracerebroventricular injection to determine the contribution of A(2A)Rs in forebrain neurons and glial cells to A(2A)R antagonist-mediated motor and neuroprotective effects. RESULTS The selective deletion of A(2A)Rs in forebrain neurons abolished the motor stimulant effects of the A(2A)R antagonist KW-6002 but did not affect acute MPTP neurotoxicity. Intracerebroventricular administration of KW-6002 into forebrain A(2A)R knock-out mice reinstated protection against acute MPTP-induced dopaminergic neurotoxicity and attenuated MPTP-induced striatal microglial and astroglial activation. INTERPRETATION A(2A)R activity in forebrain neurons is critical to the control of motor activity, whereas brain cells other than forebrain neurons (likely glial cells) are important components for protection against acute MPTP toxicity.
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Affiliation(s)
- Liqun Yu
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA
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102
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Baraldi PG, Tabrizi MA, Gessi S, Borea PA. Adenosine Receptor Antagonists: Translating Medicinal Chemistry and Pharmacology into Clinical Utility. Chem Rev 2008; 108:238-63. [DOI: 10.1021/cr0682195] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Pier Giovanni Baraldi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Mojgan Aghazadeh Tabrizi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Stefania Gessi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Pier Andrea Borea
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
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103
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Higgins GA, Grzelak ME, Pond AJ, Cohen-Williams ME, Hodgson RA, Varty GB. The effect of caffeine to increase reaction time in the rat during a test of attention is mediated through antagonism of adenosine A2A receptors. Behav Brain Res 2007; 185:32-42. [PMID: 17707919 DOI: 10.1016/j.bbr.2007.07.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Revised: 06/25/2007] [Accepted: 07/09/2007] [Indexed: 11/16/2022]
Abstract
Caffeine produces effects on cognitive function particularly relating to aspects of attention such as reaction time. Considering the plasma exposure levels following regular caffeine intake, and the affinity of caffeine for known protein targets, these effects are likely mediated by either the adenosine A(1) or A(2A) receptor. In the present studies, two rat strains [Long-Evans (LE) and CD] were trained to asymptote performance in a test of selective attention, the 5-choice serial reaction time task (5-CSRTT). Next, the effects of caffeine were compared to the selective A(2A) antagonists, SCH 412348 and KW-6002 (Istradefylline), and the A(1) antagonist, DPCPX. Further studies compared the psychostimulant effects of each drug. Finally, we tested the A(2A) agonist, CGS-21680, on 5-CSRTT performance and given the antipsychotic potential of this drug class, studied the interaction between CGS-21680 and amphetamine in this task. Caffeine (3-10mg/kg IP) increased reaction time in both LE and CD rats, with no effect on accuracy, an effect replicated by SCH 412348 (0.1-1mg/kg PO) and KW-6002 (1-3mg/kg PO), but not DPCPX (3-30 mg/kg PO). At least with SCH 412348, these effects were at doses that were not overtly psychostimulant. In contrast, CGS-21680 (0.03-0. 3mg/kg IP) slowed reaction speed and increased omissions. Interestingly, at a comparatively low dose of 0.03 mg/kg, CGS-21680 attenuated the increased premature responding produced by amphetamine (1mg/kg IP). The present results suggest that the attention-enhancing effects of caffeine are mediated through A(2A) receptor blockade, and selective A(2A) receptor antagonists may have potential as therapies for attention-related disorders. Furthermore, the improvement in response control in amphetamine-treated rats following CGS-21680 pretreatment supports the view that A(2A) agonists have potential as novel antipsychotics.
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Affiliation(s)
- Guy A Higgins
- Department of Neurobiology, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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104
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Ferré S, Diamond I, Goldberg SR, Yao L, Hourani SMO, Huang ZL, Urade Y, Kitchen I. Adenosine A2A receptors in ventral striatum, hypothalamus and nociceptive circuitry implications for drug addiction, sleep and pain. Prog Neurobiol 2007; 83:332-47. [PMID: 17532111 PMCID: PMC2141681 DOI: 10.1016/j.pneurobio.2007.04.002] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 03/15/2007] [Accepted: 04/05/2007] [Indexed: 11/22/2022]
Abstract
Adenosine A2A receptors localized in the dorsal striatum are considered as a new target for the development of antiparkinsonian drugs. Co-administration of A2A receptor antagonists has shown a significant improvement of the effects of l-DOPA. The present review emphasizes the possible application of A2A receptor antagonists in pathological conditions other than parkinsonism, including drug addiction, sleep disorders and pain. In addition to the dorsal striatum, the ventral striatum (nucleus accumbens) contains a high density of A2A receptors, which presynaptically and postsynaptically regulate glutamatergic transmission in the cortical glutamatergic projections to the nucleus accumbens. It is currently believed that molecular adaptations of the cortico-accumbens glutamatergic synapses are involved in compulsive drug seeking and relapse. Here we review recent experimental evidence suggesting that A2A antagonists could become new therapeutic agents for drug addiction. Morphological and functional studies have identified lower levels of A2A receptors in brain areas other than the striatum, such as the ventrolateral preoptic area of the hypothalamus, where adenosine plays an important role in sleep regulation. Although initially believed to be mostly dependent on A1 receptors, here we review recent studies that demonstrate that the somnogenic effects of adenosine are largely mediated by hypothalamic A2A receptors. A2A)receptor antagonists could therefore be considered as a possible treatment for narcolepsy and other sleep-related disorders. Finally, nociception is another adenosine-regulated neural function previously thought to mostly involve A1 receptors. Although there is some conflicting literature on the effects of agonists and antagonists, which may partly be due to the lack of selectivity of available drugs, the studies in A2A receptor knockout mice suggest that A2A receptor antagonists might have some therapeutic potential in pain states, in particular where high intensity stimuli are prevalent.
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Affiliation(s)
- S Ferré
- Preclinical Pharmacology Section, National Institute on Drug Abuse, Intramural Research Program, Department of Health and Human Services, Baltimore, MD 21224, USA.
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105
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Milioli EM, Cologni P, Santos CC, Marcos TD, Yunes VM, Fernandes MS, Schoenfelder T, Costa-Campos L. Effect of acute administration of hydroalcohol extract of Ilex paraguariensis St Hilaire (Aquifoliaceae) in animal models of Parkinson's disease. Phytother Res 2007; 21:771-6. [PMID: 17486685 DOI: 10.1002/ptr.2166] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ilex paraguariensis St Hilaire (Aquifoliaceae) is a plant widely cultivated in South America and with various reputed medicinal properties that can be attributed to phenolic constituents of the leaves: caffeine, theophylline and theobromine, besides the flavonoids, quercetin and rutin. This study examined the antiparkinsonian activity of the hydroalcohol extract of Ilex paraguariensis in models of protection against cerebral injury induced by MPTP and reversal of the catatonia induced by reserpine in mice. The hydroalcohol extract prevented MPTP-induced hypolocomotion at doses of 250 and 500 mg/kg at the all time points observed and also prevented the reserpine-induced catalepsy at the same doses. The extract potentiated the effect of apomorphine in preventing catatonia, suggesting a non-dopaminergic activity, probably through antagonism of adenosine. In biochemical studies the hydroalcohol extract caused a significant decrease in the NO levels, exhibited a DPPH-scavenging ability and was effective in preventing the oxidation of deoxyribose. The results obtained suggest that the hydroalcohol extract of Ilex paraguariensis may have an antiparkinsonian profile in animal models, probably through its antioxidant activity and antagonist action on adenosine A(2A) receptors.
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Affiliation(s)
- E M Milioli
- Programa de Iniciação Científica, PIC170, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil
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106
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Mihara T, Mihara K, Yarimizu J, Mitani Y, Matsuda R, Yamamoto H, Aoki S, Akahane A, Iwashita A, Matsuoka N. Pharmacological Characterization of a Novel, Potent Adenosine A1 and A2A Receptor Dual Antagonist, 5-[5-Amino-3-(4-fluorophenyl)pyrazin-2-yl]-1-isopropylpyridine-2(1H)-one (ASP5854), in Models of Parkinson's Disease and Cognition. J Pharmacol Exp Ther 2007; 323:708-19. [PMID: 17684118 DOI: 10.1124/jpet.107.121962] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Central adenosine A(2A) receptor is a promising target for drugs to treat Parkinson's disease (PD), and the central blockade of adenosine A(1) receptor improves cognitive function. In the present study, we investigated the effect of a novel adenosine A(1) and A(2A) dual antagonist, 5-[5-amino-3-(4-fluorophenyl) pyrazin-2-yl]-1-isopropylpyridine-2(1H)-one (ASP5854), in animal models of PD and cognition. The binding affinities of ASP5854 for human A(1) and A(2A) receptors were 9.03 and 1.76 nM, respectively, with higher specificity and no species differences. ASP5854 also showed antagonistic action on A(1) and A(2A) agonist-induced increases of intracellular Ca(2+) concentration. ASP5854 ameliorated A(2A) agonist 2-[p-(2-carboxyethyl) phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680)- and haloperidol-induced catalepsy in mice, with the minimum effective doses of 0.32 and 0.1 mg/kg, respectively, and it also improved haloperidol-induced catalepsy in rats at doses higher than 0.1 mg/kg. In unilateral 6-hydroxydopamine-lesioned rats, ASP5854 significantly potentiated l-dihydroxyphenylalanine (L-DOPA)-induced rotational behavior at doses higher than 0.032 mg/kg. ASP5854 also significantly restored the striatal dopamine content reduced by 1-metyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment in mice at doses higher than 0.1 mg/kg. Furthermore, in the rat passive avoidance test, ASP5854 significantly reversed the scopolamine-induced memory deficits, whereas the specific adenosine A(2A) antagonist 8-((E)-2-(3,4-dimethoxyphenyl)ethenyl)-1,3-diethyl-7-methyl-3,7-dihydro-1H-purine-2,6-dione (KW-6002; istradefylline) did not. Scopolamine- or 5H-dibenzo[a,d]cyclohepten-5,10-imine (dizocilpine maleate) (MK-801)-induced impairment of spontaneous alternation in the mouse Y-maze test was ameliorated by ASP5854, whereas KW-6002 did not exert improvement at therapeutically relevant dosages. These results demonstrate that the novel, selective, and orally active dual adenosine A(1) and A(2A) receptors antagonist ASP5854 improves motor impairments, is neuroprotective via A(2A) antagonism, and also enhances cognitive function through A(1) antagonism.
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Affiliation(s)
- Takuma Mihara
- Pharmacology Research Laboratories, Astellas Pharma Inc., Ibaraki, Japan.
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107
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O’Neill M, Brown VJ. The effect of striatal dopamine depletion and the adenosine A2A antagonist KW-6002 on reversal learning in rats. Neurobiol Learn Mem 2007; 88:75-81. [DOI: 10.1016/j.nlm.2007.03.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Revised: 02/08/2007] [Accepted: 03/06/2007] [Indexed: 11/16/2022]
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108
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Ulanowska K, Piosik J, Gwizdek-Wiśniewska A, Wegrzyn G. Impaired mutagenic activities of MPDP(+) (1-methyl-4-phenyl-2,3-dihydropyridinium) and MPP(+) (1-methyl-4-phenylpyridinium) due to their interactions with methylxanthines. Bioorg Med Chem 2007; 15:5150-7. [PMID: 17533133 DOI: 10.1016/j.bmc.2007.05.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Revised: 05/04/2007] [Accepted: 05/11/2007] [Indexed: 11/24/2022]
Abstract
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is a neurotoxin causing symptoms that resemble those observed in patients suffering from Parkinson's disease. However, in animal or human organisms, MPTP is converted to MPDP(+) (1-methyl-4-phenyl-2,3-dihydropyridinium) and further to MPP(+) (1-methyl-4-phenylpyridinium); the latter compound is the actual neurotoxin. In this report, we demonstrate that MPDP(+) and MPP(+) can form stacking complexes with methylxanthines (caffeine and penthoxifylline), which leads to significant impairment of the biological activity of these toxins (as measured by their mutagenicity).
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Affiliation(s)
- Katarzyna Ulanowska
- Department of Molecular Biology, University of Gdańsk, Kładki 24, Gdańsk, Poland
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109
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Ishiwari K, Madson LJ, Farrar AM, Mingote SM, Valenta JP, DiGianvittorio MD, Frank LE, Correa M, Hockemeyer J, Müller C, Salamone JD. Injections of the selective adenosine A2A antagonist MSX-3 into the nucleus accumbens core attenuate the locomotor suppression induced by haloperidol in rats. Behav Brain Res 2007; 178:190-9. [PMID: 17223207 PMCID: PMC2806669 DOI: 10.1016/j.bbr.2006.12.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/11/2006] [Accepted: 12/14/2006] [Indexed: 11/18/2022]
Abstract
There is considerable evidence of interactions between adenosine A2A receptors and dopamine D2 receptors in striatal areas, and antagonists of the A2A receptor have been shown to reverse the motor effects of DA antagonists in animal models. The D2 antagonist haloperidol produces parkinsonism in humans, and also induces motor effects in rats, such as suppression of locomotion. The present experiments were conducted to study the ability of the adenosine A2A antagonist MSX-3 to reverse the locomotor effects of acute or subchronic administration of haloperidol in rats. Systemic (i.p.) injections of MSX-3 (2.5-10.0 mg/kg) were capable of attenuating the suppression of locomotion induced by either acute or repeated (i.e., 14 day) administration of 0.5 mg/kg haloperidol. Bilateral infusions of MSX-3 directly into the nucleus accumbens core (2.5 microg or 5.0 microg in 0.5 microl per side) produced a dose-related increase in locomotor activity in rats treated with 0.5 mg/kg haloperidol either acutely or repeatedly. There were no overall significant effects of MSX-3 infused directly into the dorsomedial nucleus accumbens shell or the ventrolateral neostriatum. These results indicate that antagonism of adenosine A2A receptors can attenuate the locomotor suppression produced by DA antagonism, and that this effect may be at least partially mediated by A2A receptors in the nucleus accumbens core. These studies suggest that adenosine and dopamine systems interact to modulate the locomotor and behavioral activation functions of nucleus accumbens core.
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Affiliation(s)
- Keita Ishiwari
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | - Lisa J. Madson
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | - Andrew M. Farrar
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | - Susana M. Mingote
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | - John P. Valenta
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | | | - Lauren E. Frank
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
| | - Merce Correa
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
- Area de Psicobiol., Department of Psicologia, Universitat de Jaume I, Castello, Spain
| | - Jörg Hockemeyer
- Universität Bonn, Pharmazeutisches Institut, Pharmazeutische Chemie, Poppelsdorf, Bonn, Germany
| | - Christa Müller
- Universität Bonn, Pharmazeutisches Institut, Pharmazeutische Chemie, Poppelsdorf, Bonn, Germany
| | - John D. Salamone
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, United States
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110
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Silverman LS, Caldwell JP, Greenlee WJ, Kiselgof E, Matasi JJ, Tulshian DB, Arik L, Foster C, Bertorelli R, Monopoli A, Ongini E. 3H-[1,2,4]-Triazolo[5,1-i]purin-5-amine derivatives as adenosine A2A antagonists. Bioorg Med Chem Lett 2007; 17:1659-62. [PMID: 17234414 DOI: 10.1016/j.bmcl.2006.12.104] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 12/22/2006] [Indexed: 11/19/2022]
Abstract
A novel series of 3-substituted-8-aryl-[1,2,4]-triazolo[5,1-i]purin-5-amine analogs related to Sch 58261 was synthesized in order to identify potent adenosine A(2A) receptor antagonists with improved selectivity over the A(1) receptor, physiochemical properties, and pharmacokinetic profiles as compared to those of Sch 58261. As a result of structural modifications, numerous analogs with excellent in vitro binding affinities and selectivities were identified. Moreover, compound 27 displayed both superior in vitro and highly promising in vivo profiles.
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Affiliation(s)
- Lisa S Silverman
- CV & CNS Departments of Chemical Research, Schering Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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111
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Geng X, Tian X, Tu P, Pu X. Neuroprotective effects of echinacoside in the mouse MPTP model of Parkinson's disease. Eur J Pharmacol 2007; 564:66-74. [PMID: 17359968 DOI: 10.1016/j.ejphar.2007.01.084] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 11/23/2006] [Accepted: 01/17/2007] [Indexed: 10/23/2022]
Abstract
In the present study, we investigated the neuroprotective effects of echinacoside, a phenylethanoid glycoside extracted from the medicinal Chinese herb Cistanches salsa, against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic toxicity. We confirmed that exposure to MPTP in mice leads to permanent behavioral deficits and depletion of dopamine and its metabolites. When administered prior to MPTP, echinacoside reduced behavioral deficits, increased striatal dopamine and dopamine metabolite levels, reduced cell death, and led to a marked increase in tyrosine hydroxylase expression relative to mice treated with MPTP alone. In addition, pre-treatment with echinacoside significantly reduced caspase-3 and caspase-8 activation in 1-methyl-4-phenylpyridinium (MPP(+))-induced apoptosis in cerebellar granule neurons. Taken together, these findings suggest that echinacoside improves the behavioral and neurochemical outcomes in MPTP mice model of Parkinson's disease and inhibits caspase-3 and caspase-8 activation in cerebellar granule neurons, making the compound an attractive candidate treatment for various neurodegenerative disorders, including Parkinson's disease.
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Affiliation(s)
- Xingchao Geng
- Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Science, Peking University, 38 Xueyuan Road, Haidian District, 100083 Beijing, PR China
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112
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Rose S, Ramsay Croft N, Jenner P. The novel adenosine A2a antagonist ST1535 potentiates the effects of a threshold dose of l-dopa in unilaterally 6-OHDA-lesioned rats. Brain Res 2007; 1133:110-4. [PMID: 17196564 DOI: 10.1016/j.brainres.2006.10.038] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 10/05/2006] [Accepted: 10/21/2006] [Indexed: 11/21/2022]
Abstract
Adenosine A2a antagonists can modulate dopamine-mediated motor behaviours, however, their ability to induce rotational behaviour in 6-hydroxydopamine (6-OHDA)-lesioned rats and to potentiate the effects of l-dopa differs. We now report on the effects of the novel A2a antagonist ST1535 on rotational responses in this model. When administered alone, ST1535 (2.5-40 mg/kg po) enhanced exploratory behaviour and produced a dose-related increase in ipsilateral rotation in rats with a unilateral 6-OHDA lesion of the nigro-striatal pathway. Administration of ST1535 (40 mg/kg po) in combination with a high dose of l-dopa (12 mg/kg ip) caused marked contraversive rotation but did not alter the rotational response produced by l-dopa alone. In contrast, when administered in combination with l-dopa (7 mg/kg ip) that alone produced a submaximal circling response, ST1535 enhanced the intensity and duration of rotation. These results suggest that ST1535 is able to alter dopamine-mediated behaviour when given alone and to potentiate the effects of submaximal doses of l-dopa. ST1535 may be useful in the treatment of Parkinson's disease and effective in reducing the use of l-dopa.
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Affiliation(s)
- Sarah Rose
- Neurodegenerative Disease Research Centre, School of Health and Biomedical Sciences, Kings College, London SE1 1UL, UK
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113
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Konieczny J, Wardas J, Kuter K, Pilc A, Ossowska K. The influence of group III metabotropic glutamate receptor stimulation by (1S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid on the parkinsonian-like akinesia and striatal proenkephalin and prodynorphin mRNA expression in rats. Neuroscience 2007; 145:611-20. [PMID: 17224239 DOI: 10.1016/j.neuroscience.2006.12.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 12/01/2006] [Accepted: 12/01/2006] [Indexed: 10/23/2022]
Abstract
Group III metabotropic glutamate receptors (mGluRs) are widely distributed in the basal ganglia, especially on the terminals of pathways which seem to be overactive in Parkinson's disease. The aim of the present study was to determine whether (1S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid (ACPT-1), an agonist of group III mGluRs, injected bilaterally into the globus pallidus (GP), striatum or substantia nigra pars reticulata (SNr), can attenuate the haloperidol-induced catalepsy in rats, and whether that effect was related to modulation of proenkephalin (PENK) or prodynorphin (PDYN) mRNA expression in the striatum. Administration of ACPT-1 (0.05-1.6 microg/0.5 microl/side) caused a dose-and-structure-dependent decrease in the haloperidol (0.5 mg/kg i.p. or 1.5 mg/kg s.c.)-induced catalepsy whose order was as follows: GP>striatum>SNr. ACPT-1, given alone to any of those structures, induced no catalepsy in rats. Haloperidol (3 x 1.5 mg/kg s.c.) significantly increased PENK mRNA expression in the striatum, while PDYN mRNA levels were not affected by that treatment. ACPT-1 (3 x 1.6 microg/0.5 microl/side) injected into the striatum significantly attenuated the haloperidol-increased PENK mRNA expression, whereas administration of that compound into the GP or SNr did not influence the haloperidol-increased striatal PENK mRNA levels. Our results demonstrate that stimulation of group III mGluRs in the striatum, GP or SNr exerts antiparkinsonian-like effects in rats. The anticataleptic effect of intrastriatally injected ACPT-1 seems to correlate with diminished striatal PENK mRNA expression. However, since the anticataleptic effect produced by intrapallidal and intranigral injection of ACPT-1 is not related to a simultaneous decrease in striatal PENK mRNA levels, it is likely that a decrease in enkephalin biosynthesis is not a necessary condition to obtain an antiparkinsonian effect.
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Affiliation(s)
- J Konieczny
- Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Kraków, Poland.
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114
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Schapira AHV. Future directions in the treatment of Parkinson's disease. Mov Disord 2007; 22 Suppl 17:S385-91. [PMID: 18175401 DOI: 10.1002/mds.21679] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Anthony H V Schapira
- University Department of Clinical Neurosciences, Royal Free and University College Medical School, University College London, London, UK.
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115
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Pinna A, Pontis S, Borsini F, Morelli M. Adenosine A2A receptor antagonists improve deficits in initiation of movement and sensory motor integration in the unilateral 6-hydroxydopamine rat model of Parkinson's disease. Synapse 2007; 61:606-14. [PMID: 17476684 DOI: 10.1002/syn.20410] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Evidence obtained in rodent and primate models of Parkinson's disease (PD) and preliminary clinical trials, indicates that adenosine A(2A) receptor antagonists might represent a promising nondopaminergic therapeutic tool for the treatment of PD. Those studies demonstrated the ability of adenosine A(2A) receptor antagonists to potentiate l-dopa-mediated motor improvement, whereas very little is known about counteraction of specific motor deficits and on the effects of these compounds when administered alone. To this aim we evaluated the effects of different adenosine A(2A) receptor antagonists on initiation of movement deficits, gait impairment and sensory-motor deficits, induced in rats by a unilateral 6-hydroxydopamine lesion of dopaminergic nigrostriatal neurons. The following tests were used: (1) initiation time of stepping; (2) adjusting step (stepping with forelimb was measured as the forelimb was dragged laterally); (3) vibrissae-elicited forelimb placing (as index of sensory-motor integration deficits). Acute administration of the A(2A) receptor antagonists SCH 58261 (5 mg/kg i.p.) and ST 1535 (20 mg/kg i.p.) similarly to l-dopa (6 mg/kg i.p.) counteracted the impairments in the initiation time of stepping test, in the adjusting step and in the vibrissae-elicited forelimb placing induced by the lesion. The intensity of the effect was l-dopa > SCH 58261 > ST 1535. The results provide the first evidence that blockade of A(2A) receptors is effective in antagonizing specific motor deficit induced by DA neuron degeneration, such as initiation of movement and sensory-motor integration deficits, even without l-dopa combined administration.
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Affiliation(s)
- Annalisa Pinna
- Section of Cagliari, CNR Institute of Neuroscience, Cagliari, Italy
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116
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Fuxe K, Canals M, Torvinen M, Marcellino D, Terasmaa A, Genedani S, Leo G, Guidolin D, Diaz-Cabiale Z, Rivera A, Lundstrom L, Langel U, Narvaez J, Tanganelli S, Lluis C, Ferré S, Woods A, Franco R, Agnati LF. Intramembrane receptor–receptor interactions: a novel principle in molecular medicine. J Neural Transm (Vienna) 2006; 114:49-75. [PMID: 17066251 DOI: 10.1007/s00702-006-0589-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2006] [Accepted: 10/04/2006] [Indexed: 10/24/2022]
Abstract
In 1980/81 Agnati and Fuxe introduced the concept of intramembrane receptor-receptor interactions and presented the first experimental observations for their existence in crude membrane preparations. The second step was their introduction of the receptor mosaic hypothesis of the engram in 1982. The third step was their proposal that the existence of intramembrane receptor-receptor interactions made possible the integration of synaptic (WT) and extrasynaptic (VT) signals. With the discovery of the intramembrane receptor-receptor interactions with the likely formation of receptor aggregates of multiple receptors, so called receptor mosaics, the entire decoding process becomes a branched process already at the receptor level in the surface membrane. Recent developments indicate the relevance of cooperativity in intramembrane receptor-receptor interactions namely the presence of regulated cooperativity via receptor-receptor interactions in receptor mosaics (RM) built up of the same type of receptor (homo-oligomers) or of subtypes of the same receptor (RM type1). The receptor-receptor interactions will to a large extent determine the various conformational states of the receptors and their operation will be dependent on the receptor composition (stoichiometry), the spatial organization (topography) and order of receptor activation in the RM. The biochemical and functional integrative implications of the receptor-receptor interactions are outlined and long-lived heteromeric receptor complexes with frozen RM in various nerve cell systems may play an essential role in learning, memory and retrieval processes. Intramembrane receptor-receptor interactions in the brain have given rise to novel strategies for treatment of Parkinson's disease (A2A and mGluR5 receptor antagonists), schizophrenia (A2A and mGluR5 agonists) and depression (galanin receptor antagonists). The A2A/D2, A2A/D3 and A2A/mGluR5 heteromers and heteromeric complexes with their possible participation in different types of RM are described in detail, especially in the cortico-striatal glutamate synapse and its extrasynaptic components, together with a postulated existence of A2A/D4 heteromers. Finally, the impact of intramembrane receptor-receptor interactions in molecular medicine is discussed outside the brain with focus on the endocrine, the cardiovascular and the immune systems.
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Affiliation(s)
- K Fuxe
- Department of Neuroscience, Division of Cellular and Molecular Neurochemistry, Karolinska Institutet, Stockholm, Sweden.
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117
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Mojsilovic-Petrovic J, Jeong GB, Crocker A, Arneja A, David S, Russell D, Kalb RG. Protecting motor neurons from toxic insult by antagonism of adenosine A2a and Trk receptors. J Neurosci 2006; 26:9250-63. [PMID: 16957081 PMCID: PMC6674510 DOI: 10.1523/jneurosci.1856-06.2006] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The death of motor neurons in amyotrophic lateral sclerosis (ALS) is thought to result from the interaction of a variety of factors including excitotoxicity, accumulation of toxic proteins, and abnormal axonal transport. Previously, we found that the susceptibility of motor neurons to excitotoxic insults can be limited by inhibiting signals evoked by brain-derived neurotrophic factor (BDNF) activation of the receptor tyrosine kinase B (TrkB). Here we show that this can be achieved by direct kinase inhibition or by blockade of a transactivation pathway that uses adenosine A2a receptors and src-family kinases (SFKs). Downstream signaling cascades (such as mitogen-activated protein kinase and phosphatidylinositol-3 kinase) are inhibited by these blockers. In addition to protecting motor neurons from excitotoxic insult, these agents also prevent toxicity that follows from the expression of mutant proteins (G85R superoxide dismutase 1; G59S p150(glued)) that cause familial motor neuron disease. TrkB, adenosine A2a receptors, and SFKs associate into complexes in lipid raft and nonlipid raft membranes and the signaling from lipids rafts may be particularly important because their disruption by cholesterol depletion blocks the ability of BDNF to render motor neurons vulnerable to insult. The neuroprotective versatility of Trk antagonism suggests that it may have broad utility in the treatment of ALS patients.
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Affiliation(s)
- Jelena Mojsilovic-Petrovic
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
| | - Goo-Bo Jeong
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
- Department of Anatomy, College of Medicine, Chungbuk National University, Cheong-ju 361-763, Republic of Korea, and
| | - Amanda Crocker
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
| | - Amrita Arneja
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
| | - Samuel David
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
| | - David Russell
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06519
| | - Robert G. Kalb
- Department of Neurology, Children’s Hospital of Philadelphia, Joseph Stokes Jr. Research Institute, Philadelphia, Pennsylvania 19104
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118
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Jenner P. Istradefylline, a novel adenosine A2A receptor antagonist, for the treatment of Parkinson's disease. Expert Opin Investig Drugs 2006; 14:729-38. [PMID: 16004599 DOI: 10.1517/13543784.14.6.729] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Dopamine replacement therapy effectively treats the early motor symptoms of Parkinson's disease (PD). However, its association with the development of motor complications limits its usefulness in late stages of the disease. Adenosine A(2A) receptors are localised to the indirect striatal output function and control motor behaviour. They are active in predictive experimental models of PD and appear to be promising as the first major non-dopaminergic therapy for PD. Istradefylline is a novel adenosine A(2A) receptor antagonist currently in Phase III clinical trials for efficacy in patients with PD; results from Phase II clinical trials demonstrated that it provides a clinically meaningful reduction in 'off' time and an increased 'on' time with non-troublesome dyskinesia in levodopa-treated patients with established motor complications, and is safe and well tolerated.
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Affiliation(s)
- Peter Jenner
- Neurodegenerative Diseases Research Centre, GKT School of Biomedical Sciences, King's College, London SE1 1UL, UK.
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119
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Vijitruth R, Liu M, Choi DY, Nguyen XV, Hunter RL, Bing G. Cyclooxygenase-2 mediates microglial activation and secondary dopaminergic cell death in the mouse MPTP model of Parkinson's disease. J Neuroinflammation 2006; 3:6. [PMID: 16566823 PMCID: PMC1440849 DOI: 10.1186/1742-2094-3-6] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 03/27/2006] [Indexed: 12/31/2022] Open
Abstract
Background Accumulating evidence suggests that inflammation plays an important role in the progression of Parkinson's disease (PD). Among many inflammatory factors found in the PD brain, cyclooxygenase (COX), specifically the inducible isoform, COX-2, is believed to be a critical enzyme in the inflammatory response. Induction of COX-2 is also found in an experimental model of PD produced by administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Method COX-2-deficient mice or C57BL/6 mice were treated with MPTP to investigate the effects of COX-2 deficiency or by using various doses of valdecoxib, a specific COX-2 inhibitor, which induces inhibition of COX-2 on dopaminergic neuronal toxicity and locomotor activity impairment. Immunohistochemistry, stereological cell counts, immunoblotting, an automated spontaneous locomotor activity recorder and rotarod behavioral testing apparatus were used to assess microglial activation, cell loss, and behavioral impariments. Results MPTP reduced tyrosine hydroxylase (TH)-positive cell counts in the substantia nigra pars compacta (SNpc); total distance traveled, vertical activity, and coordination on a rotarod; and increased microglia activation. Valdecoxib alleviated the microglial activation, the loss of TH-positive cells and the decrease in open field and vertical activity. COX-2 deficiency attenuated MPTP-induced microglial activation, degeneration of TH-positive cells, and loss of coordination. Conclusion These results indicate that reducing COX-2 activity can mitigate the secondary and progressive loss of dopaminergic neurons as well as the motor deficits induced by MPTP, possibly by suppression of microglial activation in the SNpc.
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Affiliation(s)
- Rattanavijit Vijitruth
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Mei Liu
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Dong-Young Choi
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Xuan V Nguyen
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Randy L Hunter
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Guoying Bing
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
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120
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Ulanowska K, Piosik J, Gwizdek-Wiśniewska A, We Grzyn G. Formation of stacking complexes between caffeine (1,2,3-trimethylxanthine) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine may attenuate biological effects of this neurotoxin. Bioorg Chem 2006; 33:402-13. [PMID: 16165186 DOI: 10.1016/j.bioorg.2005.07.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2005] [Revised: 07/17/2005] [Accepted: 07/27/2005] [Indexed: 11/26/2022]
Abstract
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin causing symptoms that may resemble those observed in patients suffering from Parkinson's disease. Therefore, MPTP-treated laboratory animals are currently the most favored models to study therapeutic intervention strategies in this disease. It was demonstrated recently that caffeine (1,2,3-trimethylxanthine) intake decreases the risk of Parkinson's disease in various human populations and attenuates MPTP-induced neurological effects in animal models. Since the effects of caffeine on MPTP-treated animals were mimicked by several antagonists of the adenosine A(2A) receptor, it was suggested that caffeine attenuates MPTP toxicity by blocking this receptor. Here, using microcalorimetry and molecular modeling, we demonstrate that caffeine can form stacking (pi-pi) complexes with MPTP. We found that a biological activity of MPTP (induction of mutations in a microbiological mutagenicity assay), which is completely independent on the A(2A) receptor blockade, is significantly reduced by caffeine. Therefore, we suggest that caffeine may attenuate neurotoxicity of MPTP (and possibly other polycyclic aromatic toxins) and reveal its protective effects on the risk of Parkinson's disease not only by blocking the A(2A) receptor but also by sequestering neurotoxin molecules in mixed complexes, especially in stomach.
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Affiliation(s)
- Katarzyna Ulanowska
- Department of Molecular Biology, University of Gdańsk, Kładki 24, 80-822 Gdansk, Poland
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121
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Kachroo A, Orlando LR, Grandy DK, Chen JF, Young AB, Schwarzschild MA. Interactions between metabotropic glutamate 5 and adenosine A2A receptors in normal and parkinsonian mice. J Neurosci 2006; 25:10414-9. [PMID: 16280580 PMCID: PMC6725827 DOI: 10.1523/jneurosci.3660-05.2005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Evidence for heteromeric receptor complexes comprising adenosine A2A and metabotropic glutamate 5 (mGlu5) receptors in striatum has raised the possibility of synergistic interactions between striatal A2A and mGlu5 receptors. We investigated the role of striatal A2A receptors in the locomotor stimulant and antiparkinsonian properties of mGlu5 antagonists using complementary pharmacologic and genetic approaches. Locomotion acutely stimulated by the mGlu5 antagonist [2-methyl-6-(phenylethynyl)-pyridine (MPEP)] was absent in mGlu5 knock-out (KO) mice and was potentiated by an A2A antagonist KW-6002 [(E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methylxanthine], both in normal and in dopamine-depleted (reserpinized) mice. Conversely, the MPEP-induced motor response was markedly attenuated in single and double A2A and D2 receptor KO mice. In contrast, motor stimulation by a D1 dopamine agonist was not attenuated in the KO mice. The A2A receptor dependence of MPEP-induced motor stimulation was investigated further using a postnatal forebrain-specific conditional (Cre/loxP system) KO of the A2A receptor. MPEP loses the ability to stimulate locomotion in conditional KO mice, suggesting that this mGlu5 antagonist effect requires the postdevelopmental action of striatal A2A receptors. The potentiation of mGlu5 antagonist-induced motor stimulation by an A2A antagonist and its dependence on both D2 and forebrain A2A receptors highlight the functional interdependence of these receptors. These data also strengthen a rationale for pursuing a combinational drug strategy for enhancing the antiparkinsonian effects of A2A and mGlu5 antagonists.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Analysis of Variance
- Animals
- Animals, Newborn
- Behavior, Animal/drug effects
- Blotting, Western/methods
- Disease Models, Animal
- Dopamine Agonists/pharmacology
- Dose-Response Relationship, Drug
- Drug Synergism
- Excitatory Amino Acid Antagonists/pharmacology
- Locomotion/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Motor Activity/drug effects
- Parkinson Disease/drug therapy
- Parkinson Disease/genetics
- Parkinson Disease/metabolism
- Purines/pharmacology
- Pyridines/pharmacology
- Receptor, Adenosine A2A/deficiency
- Receptor, Adenosine A2A/physiology
- Receptor, Metabotropic Glutamate 5
- Receptors, Dopamine D2/deficiency
- Receptors, Metabotropic Glutamate/deficiency
- Receptors, Metabotropic Glutamate/physiology
- Time Factors
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Affiliation(s)
- Anil Kachroo
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts 02129, USA
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122
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O'Neill M, Brown VJ. The effect of the adenosine A(2A) antagonist KW-6002 on motor and motivational processes in the rat. Psychopharmacology (Berl) 2006; 184:46-55. [PMID: 16344986 DOI: 10.1007/s00213-005-0240-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Accepted: 10/12/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE It is well established that humans and rats respond to an imperative stimulus more rapidly as a function of the foreperiod preceding the target, and with this decrease in mean response time, there is also an increase in anticipatory (prior to the signal) responses. These changes reflect enhanced motor readiness. Also, reaction times are quicker when the cost of reward (amount of work required) is minimum. Antagonism of the adenosine A(2A) receptor has been shown to effect motor-related processes. OBJECTIVE This study examined the behavioural effects of systemic administration of the adenosine A(2A) antagonist KW-6002 in a cued reaction time task in the rat. The purpose of this study is to ascertain whether KW-6002 would enhance motor readiness and effect performance as a function of reward cost. METHODS Rats were trained on a visually cued reaction time task with variable foreperiods, and the effects of three doses of KW-6002 (0.3, 1.0 and 3.0 mg/kg systemically, compared to vehicle) were examined. RESULTS Increasing doses of KW-6002 resulted in faster reaction times and an increase in the number of anticipatory responses. KW-6002 enhanced the foreperiod effect on reaction time distributions and anticipatory responses. In addition, KW-6002 had differential effects on performance between rewarded and unrewarded trials. CONCLUSION Antagonism of adenosine A(2A) receptors by systemic KW-6002 speeds reaction time and enhanced motor preparatory processes as well as interacting with motivational processes.
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Affiliation(s)
- Martin O'Neill
- School of Psychology, University of St. Andrews, KY16 9JU Scotland, UK
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123
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Harper LK, Beckett SR, Marsden CA, McCreary AC, Alexander SPH. Effects of the A2A adenosine receptor antagonist KW6002 in the nucleus accumbens in vitro and in vivo. Pharmacol Biochem Behav 2006; 83:114-21. [PMID: 16451807 DOI: 10.1016/j.pbb.2005.12.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 11/25/2005] [Accepted: 12/20/2005] [Indexed: 11/17/2022]
Abstract
In this study, we have used the selective A 2A adenosine receptor antagonist KW6002 to investigate the function of A 2A receptors in the Lister hooded rat nucleus accumbens in vitro and in vivo. Radioligand binding studies confirmed a greater than 50-fold selectivity of KW6002 for A 2A receptors compared to A1 receptors. Release of [3H]-dopamine from nucleus accumbens slices in vitro was almost doubled in the presence of 300 nM KW6002, while GABA release was inhibited by approximately one third. In vivo, intraperitoneal administration of KW6002 (4 mg kg(-1)) increased dopamine overflow almost 4-fold in the nucleus accumbens. In behavioural testing, KW6002 elicited place preference and increased locomotor activity at 1, 2 and 4 mg kg(-1). Taken together, these results suggest a role for tonic activation of A 2A adenosine receptors in reward-related phenomena.
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Affiliation(s)
- L K Harper
- School of Biomedical Sciences and Institute of Neuroscience, University of Nottingham Medical School, Nottingham, UK
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124
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Abstract
Considerable advances made in defining the aetiology, pathogenesis, and pathology of Parkinson's disease (PD) have resulted in the development and rapid expansion of the pharmacopoeia available for treatment. Anticholinergics were used before the introduction of levodopa which is now the drug most commonly used. Dopamine agonists are effective when used alone or as an adjunct to levodopa, while monoamine oxidase B inhibitors improve motor function in early and advanced PD. However, treatment mainly addresses the dopaminergic features of the disease and leaves its progressive course unaffected; the drug treatment available for the management of non-motor symptoms is limited. This article seeks to set current treatment options in context, review emerging and novel drug treatments for PD, and assess the prospects for disease modification. Surgical therapies are not considered.
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Affiliation(s)
- A H V Schapira
- University Department of Clinical Neurosciences, Royal Free and University College Medical School, London NW3 2PF, UK.
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125
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Matasi JJ, Caldwell JP, Zhang H, Fawzi A, Cohen-Williams ME, Varty GB, Tulshian DB. 2-(2-Furanyl)-7-phenyl[1,2,4]triazolo[1,5-c]pyrimidin-5-amine analogs: Highly potent, orally active, adenosine A2A antagonists. Part 1. Bioorg Med Chem Lett 2005; 15:3670-4. [PMID: 15978806 DOI: 10.1016/j.bmcl.2005.05.086] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Revised: 05/05/2005] [Accepted: 05/11/2005] [Indexed: 11/24/2022]
Abstract
The structure-activity relationship of this novel class of compounds based on 2-(2-furanyl)-7-phenyl[1,2,4]-triazolo[1,5-c]pyrimidin-5-amine, 1, and its analogs was evaluated for their in vitro and in vivo adenosine A(2A) receptor antagonism. Several compounds displayed oral activity at 3 mg/kg in a rat catalepsy model. Specifically, compound 8g displayed an excellent in vitro profile, as well as a highly promising in vivo profile.
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Affiliation(s)
- Julius J Matasi
- Department of Medicinal Chemistry-CV & CNS, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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126
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Matasi JJ, Caldwell JP, Hao J, Neustadt B, Arik L, Foster CJ, Lachowicz J, Tulshian DB. The discovery and synthesis of novel adenosine receptor (A(2A)) antagonists. Bioorg Med Chem Lett 2005; 15:1333-6. [PMID: 15713381 DOI: 10.1016/j.bmcl.2005.01.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Revised: 01/10/2005] [Accepted: 01/11/2005] [Indexed: 10/25/2022]
Abstract
In high throughput screening of our file compounds, a novel structure 1 was identified as a potent A(2A) receptor antagonist with no selectivity over the A1 adenosine receptor. The structure-activity relationship investigation using 1 as a template lead to identification of a novel class of compounds as potent and selective antagonists of A(2A) adenosine receptor. Compound 26 was identified to be the most potent A(2A) receptor antagonist (Ki = 0.8 nM) with 100-fold selectivity over the A1 adenosine receptor.
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Affiliation(s)
- Julius J Matasi
- Department of Medicinal Chemistry-CV & CNS, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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127
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Vu CB, Pan D, Peng B, Kumaravel G, Smits G, Jin X, Phadke D, Engber T, Huang C, Reilly J, Tam S, Grant D, Hetu G, Petter RC. Novel diamino derivatives of [1,2,4]triazolo[1,5-a][1,3,5]triazine as potent and selective adenosine A2a receptor antagonists. J Med Chem 2005; 48:2009-18. [PMID: 15771443 DOI: 10.1021/jm0498396] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Piperazine derivatives of 2-furanyl[1,2,4]triazolo[1,5-a][1,3,5]triazine have recently been demonstrated to be potent and selective adenosine A(2a) receptor antagonists with oral activity in rodent models of Parkinson's disease. We have replaced the piperazinyl group with a variety of linear, monocyclic, and bicyclic diamines. Of these diamines, (R)-2-(aminomethyl)pyrrolidine is a particularly potent and selective replacement for the piperazinyl group. With this diamine component, we have been able to prepare numerous analogues with low nanomolar affinity toward the A(2a) receptor and good selectivity with respect to the A(1) receptor (>200-fold in some cases). Selected analogues from this series of [1,2,4]triazolo[1,5-a][1,3,5]triazine have now been shown to be orally active in the mouse catalepsy model.
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Affiliation(s)
- Chi B Vu
- Department of Medicinal Chemistry, Biogen Idec, Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA.
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128
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Kiselgof E, Tulshian DB, Arik L, Zhang H, Fawzi A. 6-(2-Furanyl)-9H-purin-2-amine derivatives as A2A adenosine antagonists. Bioorg Med Chem Lett 2005; 15:2119-22. [PMID: 15808481 DOI: 10.1016/j.bmcl.2005.02.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 02/08/2005] [Accepted: 02/09/2005] [Indexed: 11/28/2022]
Abstract
Structure-activity relationships have been investigated through substitutions at the 9-position of the 2-amino-6-(2-furanyl) purine (5) to identify novel and selective A(2A) adenosine receptor antagonists. Several potent and selective antagonists were identified. In particular, compounds 20, 25, and 26 show very high affinity with excellent selectivity.
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Affiliation(s)
- Eugenia Kiselgof
- Schering-Plough Research Institute, Chemical Research, 2015 Galloping Hill Road, MS 2545, Kenilworth, NJ 07033, USA
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129
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Pinna A, Volpini R, Cristalli G, Morelli M. New adenosine A2A receptor antagonists: Actions on Parkinson's disease models. Eur J Pharmacol 2005; 512:157-64. [PMID: 15840400 DOI: 10.1016/j.ejphar.2005.01.057] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 01/25/2005] [Accepted: 01/31/2005] [Indexed: 11/30/2022]
Abstract
The 8-substituted 9-ethyladenine derivatives: 8-bromo-9-ethyladenine (ANR 82), 8-ethoxy- 9-ethyladenine (ANR 94), and 8-furyl-9-ethyladenine (ANR 152) have been characterized in vitro as adenosine receptor antagonists. Adenosine is deeply involved in the control of motor behaviour and substantial evidences indicate that adenosine A(2A) receptor antagonists improve motor deficits in animal models of Parkinson's disease. On this basis, the efficacy of ANR 82, ANR 94, and ANR 152 in rat models of Parkinson's disease was evaluated. All compounds tested reversed the catalepsy induced by haloperidol. However, in unilaterally 6-hydroxydopamine-lesioned rats, only ANR 94 and ANR 152 potentiated l-dihydroxy-phenylalanine (l-DOPA) effect on turning behaviour and induced contralateral turning behaviour in rats sensitised to l-DOPA. Taken together the results of this study indicate that some 8-substituted 9-ethyladenine derivatives ameliorate motor deficits in rat models of Parkinson's disease, suggesting a potential therapeutic role of these compounds.
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Affiliation(s)
- Annalisa Pinna
- CNR Institute for Neuroscience-section Cagliari, Cagliari, Italy
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130
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Xu K, Bastia E, Schwarzschild M. Therapeutic potential of adenosine A2A receptor antagonists in Parkinson's disease. Pharmacol Ther 2005; 105:267-310. [PMID: 15737407 DOI: 10.1016/j.pharmthera.2004.10.007] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Accepted: 10/14/2004] [Indexed: 10/26/2022]
Abstract
In the pursuit of improved treatments for Parkinson's disease (PD), the adenosine A(2A) receptor has emerged as an attractive nondopaminergic target. Based on the compelling behavioral pharmacology and selective basal ganglia expression of this G-protein-coupled receptor, its antagonists are now crossing the threshold of clinical development as adjunctive symptomatic treatment for relatively advanced PD. The antiparkinsonian potential of A(2A) antagonism has been boosted further by recent preclinical evidence that A(2A) antagonists might favorably alter the course as well as the symptoms of the disease. Convergent epidemiological and laboratory data have suggested that A(2A) blockade may confer neuroprotection against the underlying dopaminergic neuron degeneration. In addition, rodent and nonhuman primate studies have raised the possibility that A(2A) receptor activation contributes to the pathophysiology of dyskinesias-problematic motor complications of standard PD therapy--and that A(2A) antagonism might help prevent them. Realistically, despite being targeted to basal ganglia pathophysiology, A(2A) antagonists may be expected to have other beneficial and adverse effects elsewhere in the central nervous system (e.g., on mood and sleep) and in the periphery (e.g., on immune and inflammatory processes). The thoughtful design of new clinical trials of A(2A) antagonists should take into consideration these counterbalancing hopes and concerns and may do well to shift toward a broader set of disease-modifying as well as symptomatic indications in early PD.
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Affiliation(s)
- Kui Xu
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, MA 02129, USA
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131
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IJzerman AP, Wijngaarden IV, Soudijn W. Allosteric modulation of G-protein-coupled receptors. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.11.12.1889] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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132
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Yao G, Haque S, Sha L, Kumaravel G, Wang J, Engber TM, Whalley ET, Conlon PR, Chang H, Kiesman WF, Petter RC. Synthesis of alkyne derivatives of a novel triazolopyrazine as A2A adenosine receptor antagonists. Bioorg Med Chem Lett 2005; 15:511-5. [PMID: 15664803 DOI: 10.1016/j.bmcl.2004.11.062] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 11/18/2004] [Accepted: 11/24/2004] [Indexed: 11/20/2022]
Abstract
A novel [1,2,4]triazolo[1,5-a]pyrazine core was synthesized and coupled with terminal acetylenes. The structure-activity relationship of the alkynes from this novel template was studied for their in vitro and in vivo adenosine A(2A) receptor antagonism. Selected compounds from this series were shown to have potent in vitro and in vivo activities against adenosine A(2A) receptor. Compound 12, in particular, was found to be orally active at 3mg/kg in both a mouse catalepsy model and a 6-hydroxydopamine-lesioned rat model.
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Affiliation(s)
- Gang Yao
- Departments of Medicinal Chemistry and Pharmacology, Biogen Idec, 14 Cambridge Center, Cambridge, MA 02142, USA.
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133
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Peng H, Kumaravel G, Yao G, Sha L, Wang J, Van Vlijmen H, Bohnert T, Huang C, Vu CB, Ensinger CL, Chang H, Engber TM, Whalley ET, Petter RC. Novel bicyclic piperazine derivatives of triazolotriazine and triazolopyrimidines as highly potent and selective adenosine A2A receptor antagonists. J Med Chem 2005; 47:6218-29. [PMID: 15566292 DOI: 10.1021/jm0494321] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of bicyclic piperazine derivatives of triazolotriazine and triazolopyrimidines was synthesized. Some of these analogues show high affinity and excellent selectivity for adenosine A(2a) receptor versus the adenosine A(1) receptor. Structure-activity-relationship (SAR) studies based on octahydropyrrolo[1,2-a]pyrazine and octahydropyrido[1,2-a]pyrazine with various capping groups are reported. Among these analogues, the most potent and selective A(2a) antagonist 26 h has a K(i) value of 0.2 nM and is 16 500-fold selective with respect to the A(1) receptor. Among a number of compounds tested, compounds 21a and 21c exhibited significantly improved metabolic stability. Compounds 21a, 21c, and 18a showed good oral efficacy in rodent catalepsy models of Parkinson's disease.
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Affiliation(s)
- Hairuo Peng
- Department of Medicinal Chemistry, Biogen Idec Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA.
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134
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Fredholm BB, Chen JF, Cunha RA, Svenningsson P, Vaugeois JM. Adenosine and Brain Function. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 63:191-270. [PMID: 15797469 DOI: 10.1016/s0074-7742(05)63007-3] [Citation(s) in RCA: 500] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet Stockholm, Sweden
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135
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Abstract
Long-term disability in Parkinson's disease (PD) is related to progression of the underlying disease and the emergence of complications of chronic levodopa therapy. There is a need for new medications that can slow the underlying progression of degeneration, improve PD symptoms in early disease without inducing dyskinesia, and improve motor fluctuations and 'off' time in advanced disease without worsening dyskinesia. Much interest has focused on the development of nondopaminergic therapies, with antagonists of the adenosine A2A receptor emerging as leading candidates. A2A receptors are selectively expressed in the basal ganglia and specific A2A antagonists reverse motor deficits without causing dyskinesia in animal models of PD. The antiparkinsonian potential of A2A receptor blockade has been expanded further by convergent epidemiological and laboratory findings suggesting a possible neuroprotective effect of A2A receptor antagonists in PD. Istradefylline (KW-6002) is the first of several adenosine A2A receptor antagonists in development for PD to advance to phase III clinical trials. Initial studies indicate that in patients with motor fluctuations on levodopa, addition of istradefylline reduces 'off' time. Additional studies are necessary to evaluate the benefit of istradefylline as monotherapy in early disease, its effect on the development of dyskinesia, and its effect on disease progression.
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Affiliation(s)
- Robert A Hauser
- Department of Neurology, University of South Florida and Tampa General Healthcare, Tampa, Florida 33606, USA.
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136
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Vu CB, Shields P, Peng B, Kumaravel G, Jin X, Phadke D, Wang J, Engber T, Ayyub E, Petter RC. Triamino derivatives of triazolotriazine and triazolopyrimidine as adenosine A2a receptor antagonists. Bioorg Med Chem Lett 2004; 14:4835-8. [PMID: 15341934 DOI: 10.1016/j.bmcl.2004.07.048] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Revised: 07/20/2004] [Accepted: 07/22/2004] [Indexed: 11/30/2022]
Abstract
Piperazine derivatives of 2-furanyl[1,2,4]triazolo[1,5-a][1,3,5]triazine have recently been shown to be potent and selective adenosine A(2a) receptor antagonists. We now demonstrate that potent and selective A(2a) receptor antagonists could still be obtained when the arylpiperazines are separated from the triazolotriazine core structure by an ethylenediamine spacer. Selected analogs bearing this triazolotriazine or the related triazolopyrimidine core structure have been found to be orally active in a mouse catalepsy model of Parkinson's disease.
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Affiliation(s)
- Chi B Vu
- Biogen Idec, Inc., Department of Medicinal Chemistry, 14 Cambridge Center, Cambridge, MA 02142, USA.
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137
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Tanganelli S, Sandager Nielsen K, Ferraro L, Antonelli T, Kehr J, Franco R, Ferré S, Agnati LF, Fuxe K, Scheel-Krüger J. Striatal plasticity at the network level. Focus on adenosine A2A and D2 interactions in models of Parkinson's Disease. Parkinsonism Relat Disord 2004; 10:273-80. [PMID: 15196505 DOI: 10.1016/j.parkreldis.2004.02.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Accepted: 02/23/2004] [Indexed: 10/26/2022]
Abstract
Behavioral and microdialysis studies have been performed on antagonistic A(2A)/D(2) interactions in animal models of Parkinson's Disease. The behavioral analysis involved studies on locomotor activity in reserpinized mice, haloperidol-induced catalepsy in rats and rotational behavior in rats with unilateral 6-OHDA lesions of the ascending DA pathways (Ungerstedt model). Dual probe microdialysis studies were indirectly performed on the striatopallidal GABA neurons by studying extracellular glutamate levels in the striatum and globus pallidus of the awake freely moving rat. The striatum was perfused with A(2A) and/or D(2) agonists via reverse microdialysis. The results show that the A(2A) antagonists SCH58261 and KF17837 can increase locomotor activity in reserpinized mice and produce contralateral rotational behavior only after administration of subthreshold doses of l-DOPA or the D(2) like agonist quinpirole. Furthermore, antagonizing the A(2A) receptor (R) reduced haloperidol induced catalepsy. The behavioral results underline the view that A(2A) antagonists act by blocking A(2A) R in A(2A)/D(2) heterodimers where A(2A) R inhibits the D(2) R transduction and D(2) inhibits the adenylate cyclase (AC) activated by A(2A) R. The microdialysis studies show that the A(2A) agonist CGS21680 striatally coperfused with the D(2) agonist quinpirole more potently counteract the D(2) agonist (quinpirole) induced reduction of pallidal glutamate levels in the DA denervated vs the control striatum indicating an enhancement of the inhibitory A(2A)/D(2) interaction. In the DA denervated but not in the control striatum the A(2A) agonist CGS21680 could strongly increase striatal glutamate levels, indicating an increased receptor signaling in the A(2A) R located on the striatal glutamate terminals, where also D(2) like R exist, here probably as D(4). Thus, the signaling of this A(2A) R may be set free by the loss of D(4) tone on the AC activated by A(2A) in this postulated A(2A)/D(4) heteromer on the glutamate terminals. Taken together, the results indicate that the antiparkinsonian actions of A(2A) antagonists probably are produced by blockade of A(2A) R in the A(2A)/D(2) heterodimers mainly located in the striatopallidal GABA neurons.
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Affiliation(s)
- S Tanganelli
- Department of Clinical and Experimental Medicine, Section of Pharmacology, University of Ferrara, Ferrara, Italy
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138
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Kase H, Mori A, Jenner P. Adenosine A2A-receptor antagonists: beyond dopaminergic therapies for Parkinson's disease. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.ddstr.2004.08.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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139
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Vu CB, Peng B, Kumaravel G, Smits G, Jin X, Phadke D, Engber T, Huang C, Reilly J, Tam S, Grant D, Hetu G, Chen L, Zhang J, Petter RC. Piperazine derivatives of [1,2,4]triazolo[1,5-a][1,3,5]triazine as potent and selective adenosine A2a receptor antagonists. J Med Chem 2004; 47:4291-9. [PMID: 15294001 DOI: 10.1021/jm0498405] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The [1,2,4]triazolo[1,5-a]triazine derivative 3, more commonly known in the field of adenosine research as ZM-241385, has previously been demonstrated to be a potent and selective adenosine A2a receptor antagonist, although with limited oral bioavailability. This [1,2,4]triazolo[1,5-a]triazine core structure has now been improved by incorporating various piperazine derivatives. With some preliminary optimization, the A2a binding affinity of some of the best piperazine derivatives is almost as good as that of compound 3. The selectivity level over the adenosine A1 receptor subtype for some of the more active analogues is also fairly high, > 400-fold in some cases. Many compounds within this piperazine series of [1,2,4]triazolo[1,5-a]triazine have now been shown to have good oral bioavailability in the rat, with some as high as 89% (compound 35). More significantly, some piperazines derivatives of [1,2,4]triazolo[1,5-a]triazine also possessed good oral efficacy in rodent models of Parkinson's disease. For instance, compound 34 was orally active in the rat catalepsy model at 3 mg/kg. In the 6-hydroxydopamine-lesioned rat model, this compound was also quite effective, with a minimum effective dose of 3 mg/kg po.
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Affiliation(s)
- Chi B Vu
- Department of Medicinal Chemistry, Biogen Idec, Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA.
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140
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Correa M, Wisniecki A, Betz A, Dobson DR, O'Neill MF, O'Neill MJ, Salamone JD. The adenosine A2A antagonist KF17837 reverses the locomotor suppression and tremulous jaw movements induced by haloperidol in rats: possible relevance to parkinsonism. Behav Brain Res 2004; 148:47-54. [PMID: 14684247 DOI: 10.1016/s0166-4328(03)00178-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent evidence indicates that adenosine A2A receptors modulate the activity of striatal neurons, and that antagonists of this receptor may have actions in various animal models related to motor function. Four experiments were conducted to study the effects of systemic injections of the adenosine A2A antagonist KF17837 on the behavioral effects produced by repeated administration of the dopamine (DA) antagonist haloperidol. In the first two experiments, it was shown that repeated 0.5 mg/kg haloperidol severely suppressed open-field locomotor activity, and that KF17837 (0.0-20.0 mg/kg) did not significantly increase open-field locomotor activity. The third experiment demonstrated that injections of KF17837 (0.0-20.0 mg/kg) completely reversed the suppression of locomotion induced by haloperidol, and also increased rearing behavior in haloperidol-treated rats. Previous research has reported that haloperidol induces tremulous jaw movements that have many of the characteristics of parkinsonian tremor. The fourth experiment demonstrated that i.p. injections of KF17837 (0.0-20.0 mg/kg) also suppressed haloperidol-induced tremulous jaw movements. Taken together, the results of these experiments indicate that adenosine A2A antagonism can reverse the locomotor suppression and tremulous movements induced by DA antagonism. This profile of activity is consistent with the hypothesis that antagonism of adenosine A2A receptors can result in an antiparkinsonian effect in animal models.
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Affiliation(s)
- M Correa
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
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141
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Marino MJ, Valenti O, O'Brien JA, Williams DL, Conn PJ. Modulation of inhibitory transmission in the rat globus pallidus by activation of mGluR4. Ann N Y Acad Sci 2004; 1003:435-7. [PMID: 14684481 DOI: 10.1196/annals.1300.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Michael J Marino
- Neuroscience Department, Merck Research Laboratories, Merck Company Inc., West Point, Pennsylvania 19486, USA.
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142
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Ochi M, Shiozaki S, Kase H. Adenosine A2A receptor-mediated modulation of GABA and glutamate release in the output regions of the basal ganglia in a rodent model of Parkinson's disease. Neuroscience 2004; 127:223-31. [PMID: 15219684 DOI: 10.1016/j.neuroscience.2004.04.050] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2004] [Indexed: 11/21/2022]
Abstract
A target neuron of adenosine A(2A) receptor antagonists to exert anti-parkinsonian activities has been currently identified to be, at least in part, striatopallidal medium spiny neurons (MSNs). In the present study, we determine whether A(2A) receptor-mediated modulation is associated with changes in the release of GABA and glutamate in the substantia nigra pars reticulata (SNr), an output structure of the whole basal ganglia network, using in vivo microdialysis in a rat Parkinson's disease (PD) model. In 6-hydroxydopamine (OHDA)-lesioned rats compared with normal rats, basal extracellular GABA levels in the SNr show no change, whereas basal glutamate levels are significantly increased. Oral administration of the A(2A) receptor-selective antagonist (E-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1-H-purine-2,6-dion (KW-6002) to 6-OHDA-lesioned rats at 1 mg/kg caused a marked and sustained increase of GABA and glutamate levels in the SNr. The increase of nigral glutamate by KW-6002 was abolished by a kainic acid-induced lesion of the globus pallidus (GP) or subthalamic nucleus (STN) in 6-OHDA-lesioned rats, whereas the increase of nigral GABA was completely blocked by the GP-lesion but only partially blocked by the STN-lesion. These results indicate that changes in neurotransmitter release in the SNr brought about by KW-6002 are largely attributable to blockade of A(2A) receptor-mediated modulation of striatopallidal MSNs. Thus, these actions of KW-6002 on striatopallidal MSNs may be the main mechanism for ameliorating PD by A(2A) antagonists.
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Affiliation(s)
- M Ochi
- Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd, Nagaizumi, Sunto, Shizuoka 411-8731, Japan
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143
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Hamann M, Meisler MH, Richter A. Motor disturbances in mice with deficiency of the sodium channel gene Scn8a show features of human dystonia. Exp Neurol 2003; 184:830-8. [PMID: 14769375 DOI: 10.1016/s0014-4886(03)00290-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2003] [Revised: 05/08/2003] [Accepted: 05/23/2003] [Indexed: 11/16/2022]
Abstract
The med(J) mouse with twisting movements related to deficiency of the sodium channel Scn8a has been proposed as a model of kinesiogenic dystonia. This prompted us to examine the phenotype of these mice in more detail. By cortical electroencephalographic (EEG) recordings, we could not detect any changes, demonstrating that the motor disturbances are not epileptic in nature, an important similarity to human dystonia. The significantly decreased body weight of med(J) mice was related to reduced food intake. Observations in the open field and by video recordings revealed that the mice exhibit sustained abnormal postures and movements of limbs, trunk and tail not only during locomotor activity but also at rest. With the exception of the head tremor, the other motor impairments were persistent rather than paroxysmal. When several neurological reflexes were tested, alterations were restricted to the posture and righting reflexes. Results of the wire hang test confirmed the greatly reduced muscle strength in the med(J) mouse. In agreement with different types of human dystonia, biperiden, haloperidol and diazepam moderately reduced the severity of motor disturbances in med(J) mice. In view of the sodium channel deficiency in med(J) mice, the beneficial effects of the sodium channel blocker phenytoin was an unexpected finding. By immunohistochemical examinations, the density of nigral dopaminergic neurons was found to be unaltered, substantiating the absence of pathomorphological abnormalities within the brain of med(J) mice shown by previous studies. With the exception of muscle weakness, many of the features of the med(J) mouse are similar to human idiopathic dystonia.
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Affiliation(s)
- Melanie Hamann
- Department of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, Koserstrasse 20, 14195 Berlin, Germany.
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144
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Abstract
The globus pallidus (GP) is a key GABAergic nucleus in the basal ganglia (BG). The predominant input to the GP is an inhibitory striatal projection that forms the first synapse in the indirect pathway. The GP GABAergic neurons project to the subthalamic nucleus, providing an inhibitory control of these glutamatergic cells. Given its place within the BG circuit, it is not surprising that alterations in GP firing pattern are postulated to play a role in both normal and pathological motor behavior. Because the inhibitory striatal input to the GP may play an important role in shaping these firing patterns, we set out to determine the role that the group III metabotropic glutamate receptors (GluRs) play in modulating transmission at the striatopallidal synapse. In rat midbrain slices, electrical stimulation of the striatum evoked GABA(A)-mediated IPSCs recorded in all three types of GP neurons. The group III mGluR-selective agonist L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) inhibited these IPSCs through a presynaptic mechanism of action. L-AP4 exhibited high potency and a pharmacological profile consistent with mediation by mGluR4. Furthermore, the effect of L-AP4 on striatopallidal transmission was absent in mGluR4 knock-out mice, providing convincing evidence that mGluR4 mediates this effect. The finding that mGluR4 may selectively modulate striatopallidal transmission raises the interesting possibility that activation of mGluR4 could decrease the excessive inhibition of the GP that has been postulated to occur in Parkinson's disease. Consistent with this, we find that intracerebroventricular injections of L-AP4 produce therapeutic benefit in both acute and chronic rodent models of Parkinson's disease.
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145
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Agnati LF, Ferré S, Lluis C, Franco R, Fuxe K. Molecular mechanisms and therapeutical implications of intramembrane receptor/receptor interactions among heptahelical receptors with examples from the striatopallidal GABA neurons. Pharmacol Rev 2003; 55:509-50. [PMID: 12869660 DOI: 10.1124/pr.55.3.2] [Citation(s) in RCA: 244] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The molecular basis for the known intramembrane receptor/receptor interactions among G protein-coupled receptors was postulated to be heteromerization based on receptor subtype-specific interactions between different types of receptor homomers. The discovery of GABAB heterodimers started this field rapidly followed by the discovery of heteromerization among isoreceptors of several G protein-coupled receptors such as delta/kappa opioid receptors. Heteromerization was also discovered among distinct types of G protein-coupled receptors with the initial demonstration of somatostatin SSTR5/dopamine D2 and adenosine A1/dopamine D1 heteromeric receptor complexes. The functional meaning of these heteromeric complexes is to achieve direct or indirect (via adapter proteins) intramembrane receptor/receptor interactions in the complex. G protein-coupled receptors also form heteromeric complexes involving direct interactions with ion channel receptors, the best example being the GABAA/dopamine D5 receptor heteromerization, as well as with receptor tyrosine kinases and with receptor activity modulating proteins. As an example, adenosine, dopamine, and glutamate metabotropic receptor/receptor interactions in the striatopallidal GABA neurons are discussed as well as their relevance for Parkinson's disease, schizophrenia, and drug dependence. The heterodimer is only one type of heteromeric complex, and the evidence is equally compatible with the existence of higher order heteromeric complexes, where also adapter proteins such as homer proteins and scaffolding proteins can exist. These complexes may assist in the process of linking G protein-coupled receptors and ion channel receptors together in a receptor mosaic that may have special integrative value and may constitute the molecular basis for some forms of learning and memory.
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Affiliation(s)
- Luigi F Agnati
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden.
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146
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Villanueva-Toledo J, Moo-Puc RE, Góngora-Alfaro JL. Selective A2A, but not A1 adenosine antagonists enhance the anticataleptic action of trihexyphenidyl in rats. Neurosci Lett 2003; 346:1-4. [PMID: 12850533 DOI: 10.1016/s0304-3940(03)00337-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In rats made cataleptic with haloperidol (5.32 micromol/kg), the bar test was used to assess the possible synergism between the muscarinic antagonist trihexyphenidyl (THP) and selective adenosine A(1) and A(2A) receptor antagonists. Neither catalepsy intensity nor latency were affected by a subthreshold dose of THP (0.33 micromol/kg). The selective adenosine A(1) antagonist 8-cyclopentyl-1,3-dipropyl-xanthine (DPCPX) (5.15 micromol/kg) caused a small, but significant reduction of catalepsy intensity that remained unchanged when combined with THP. DPCPX had no effect on catalepsy latency, either alone or combined with THP. In contrast, an equimolar dose of the selective adenosine A(2A) antagonist 4-(2-[7-amino-2-(2-furyl)1,2,4-triazolo[2,3-a]-[1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385) (5.15 micromol/kg) produced a significant reduction of catalepsy intensity and increased catalepsy latency. Both effects were potentiated when ZM 241385 was combined with THP. The synergism was more evident when rats were pretreated with a subthreshold dose of ZM 241385 (1.55 micromol/kg) that was unable to modify catalepsy parameters when applied alone, but produced a significant reduction in catalepsy intensity and an increase in catalepsy latency when administered with THP. Catalepsy was unaffected by a combination of equimolar, subthreshold doses of DPCPX (1.55 micromol/kg) and ZM 241385 (1.55 micromol/kg). These findings indicate that the anticataleptic effect of anticholinergics is enhanced only by the selective blockade of adenosine A(2A) receptors.
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Affiliation(s)
- Jairo Villanueva-Toledo
- Laboratorio de Neurofisiología, Centro de Investigaciones Regionales, "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Avenida Itzáes No 490, Yucatán, Mérida CP 97000, Mexico
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147
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Wardas J, Pietraszek M, Dziedzicka-Wasylewska M. SCH 58261, a selective adenosine A2A receptor antagonist, decreases the haloperidol-enhanced proenkephalin mRNA expression in the rat striatum. Brain Res 2003; 977:270-7. [PMID: 12834887 DOI: 10.1016/s0006-8993(03)02759-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the striatum, dopamine D(2) receptors are co-localized with adenosine A(2A) receptors on the GABAergic neurons of the striopallidal pathway. Moreover, blockade of A(2A) receptors has been previously shown to suppress parkinsonian-like symptoms (catalepsy, akinesia, muscle rigidity) in rodent and primate models of Parkinson's disease (PD). Since it is believed that main motor symptoms of PD are due to the overactivity of the GABAergic striopallidal pathway, the aim of the present study was to find out whether SCH 58261, a selective antagonist of the adenosine A(2A) receptors, is capable of counteracting both the catalepsy and the enhancement of proenkephalin (PENK) mRNA expression in the rat striatum, induced by haloperidol administered at 1.5 mg/kg s.c. 3 times, every 3 h. Systemic administration of SCH 58261 (5 mg/kg i.p., 3 times, every 3 h, 10 min before haloperidol), partially decreased the haloperidol-induced catalepsy and the increase in the PENK mRNA expression in both dorsolateral and ventrolateral parts of the striatum at all three examined levels. No such changes were seen in the medial striatum and in the nucleus accumbens. Moreover, SCH 58261 given alone did not influence the level of PENK mRNA in any examined part of the striatum. The present results suggest that similarly to other A(2A) receptor antagonists, SCH 58261 normalizes activity of the striopallidal pathway, enhanced by blockade of dopamine D(2) receptors with haloperidol, which may result in recovery of motor functions.
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Affiliation(s)
- Jadwiga Wardas
- Department of NeuroPsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna St., 31-343 Kraków, Poland.
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148
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Chen JF, Schwarzschild MA. Gene knockout approach to adenosine A2A receptors in Parkinson's disease. Drug Dev Res 2003. [DOI: 10.1002/ddr.10215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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149
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Petzer JP, Steyn S, Castagnoli KP, Chen JF, Schwarzschild MA, Van der Schyf CJ, Castagnoli N. Inhibition of monoamine oxidase B by selective adenosine A2A receptor antagonists. Bioorg Med Chem 2003; 11:1299-310. [PMID: 12628657 DOI: 10.1016/s0968-0896(02)00648-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Adenosine receptor antagonists that are selective for the A(2A) receptor subtype (A(2A) antagonists) are under investigation as possible therapeutic agents for the symptomatic treatment of the motor deficits associated with Parkinson's disease (PD). Results of recent studies in the MPTP mouse model of PD suggest that A(2A) antagonists may possess neuroprotective properties. Since monoamine oxidase B (MAO-B) inhibitors also enhance motor function and reduce MPTP neurotoxicity, we have examined the MAO-B inhibiting properties of several A(2A) antagonists and structurally related compounds in an effort to determine if inhibition of MAO-B may contribute to the observed neuroprotection. The results of these studies have established that all of the (E)-8-styrylxanthinyl derived A(2A) antagonists examined display significant MAO-B inhibitory properties in vitro with K(i) values in the low micro M to nM range. Included in this series is (E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methylxanthine (KW-6002), a potent A(2A) antagonist and neuroprotective agent that is in clinical trials. The results of these studies suggest that MAO-B inhibition may contribute to the neuroprotective potential of A(2A) receptor antagonists such as KW-6002 and open the possibility of designing dual targeting drugs that may have enhanced therapeutic potential in the treatment of PD.
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Affiliation(s)
- Jacobus P Petzer
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061-0212, USA
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150
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Bonina F, Puglia C, Rimoli MG, Melisi D, Boatto G, Nieddu M, Calignano A, La Rana G, De Caprariis P. Glycosyl derivatives of dopamine and L-dopa as anti-Parkinson prodrugs: synthesis, pharmacological activity and in vitro stability studies. J Drug Target 2003; 11:25-36. [PMID: 12852438 DOI: 10.1080/1061186031000086090] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Novel glycosyl derivatives of dopamine and L-dopa (I-IV) are synthesized in order to overcome the problem of blood-brain barrier low permeability of dopamine and of low bioavailability of its precursor L-dopa. Esters synthesized link dopamine and L-dopa, by a succinyl linker, to C-3 position of glucose (I and II) and to C-6 of galactose (II and IV). The chemical and enzymatic stabilities of esters synthesized were evaluated in order to determine both their stability in aqueous medium and their feasibility in undergoing enzymatic cleavage by rat plasma to regenerate the original drug. Furthermore, we have shown the central effects of esters I-IV on classic dopaminergic models, such as morphine induced locomotion and reserpine-induced hypolocomotion. From the result obtained compounds I-IV appeared moderately stable in a pH 7.4 buffered solution and in rat plasma. Furthermore, pharmacological studies showed that both dopamine derivatives (I and II) were equiactive in reversing reserpine-induced hypolocomotion in rats, and both were more active than L-dopa or ester III and IV, while II and III were more potent in reducing morphine-induced locomotion than I and IV. The minimal vascular effects of these derivatives allow us to underline the possibility to use them in pathologies, such as Parkinson disease, characterised by an evident decreasing of dopamine concentration in the brain.
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Affiliation(s)
- Francesco Bonina
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Catania, Viale A.Doria no 6, 95125 Catania, Italy.
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